The present invention is related to wireless networks, and in particular to a method and system for broadcasting media via a wireless local area network (WLAN) using a hierarchical channel structure.
Wireless local area networks (WLANs) such as wireless networks conforming to the IEEE 802.11 standard are being rapidly deployed, e.g., to provide users with access to corporate IT networks, and to provide access to the Internet. For example, WLANs are being deployed in office environments, hot spots such as airports, camping sites, cafes, etc., and also in municipalities in the form of outdoor mesh networks.
WLANs provide for unicast communication, and also provide for extending the MAC-level broadcast/multicast mechanism out to radio interfaces. Broadcast/multicast adaptation to WLAN works well for data. However, present day IEEE 802.11 multicast/broadcast is not well suited to dealing with time-sensitive applications such as audio and/or video (in general multimedia).
With the present day IEEE 802.11 standard, transmissions of broadcast/multicast data is required to line up with DTIM beacons so that power saving can be implemented. To allow more bandwidth for client communications, there can be multiple beacon intervals between two consecutive DTIM beacons. Such scheduling does not favor time-sensitive traffic such as voice and video.
In addition, with the present day IEEE 802.11 standard, the channel structure is flat. For purposes of broadcasting media data, it would be advantageous to broadcast a directory or other information about what media is being broadcast, as well as the actual media that the directory informs on. The existing IEEE 802.11 broadcast/multicast mechanism has no provision for such a hierarchy of information. The one plain, flat structure with absence of a directory makes it hard for users to select media to receive. It also would be advantageous to provide a mechanism for charging for programming. Having a hierarchy of information would provide for viewers to see what is being charged for what programming.
Thus there is a need in the art for a mechanism suitable for broadcasting media such as audio and/or video over wireless networks, e.g., WLANs.